An astronomy satellite launched by NASA in 1999 July,
specially designed to detect X-ray emission from very hot regions of
the Universe such as exploded stars, clusters of galaxies, and matter around black holes.
Chandra carries a high resolution mirror (aperture 1.2 m, focal length 10 m),
two imaging detectors (HRC and ACIS),
and two sets of transmission grating spectrometer (LETG and HETG). Important Chandra
features are: an order of magnitude improvement in spatial resolution,
good sensitivity from 0.1 to 10 keV, and the capability for high
spectral resolution observations over most of this range.
Chandra was initially given an expected lifetime of 5 years, but
on 4 September 2001 NASA extended its lifetime to 10 years "based on
the observatory's outstanding results." Among the results obtained using
Chandra one can mention the spectacular image of the
→ supernova remnant Cassiopeia A. See also
→ X-ray astronomy.